Analýza výsledků reálných aukcí

This bachelor's thesis examines behavioral anomalies in internet auctions on the eBay platform, focusing on the phenomenon of the Winner’s Curse. The theoretical framework is the discrepancy between the rational actor model and the actual decision-making of bidders, which is often influenced by emotions and cognitive biases. The aim of this thesis is to empirically verify the occurrence of the Winner’s Curse and analyze the key auction parameters that lead to inefficient behavior. The research uses a unique dataset with information on 196 auctions of American Silver Eagle bullion coins from late 2025 and early 2026. Retail prices from the company APMEX were used to determine the objective market value of the coins. Logistic and linear regression econometric models are applied to test the hypotheses. The results of the analysis show that although most bidders behave rationally and do not overpay for the coins, there are statistically significant factors that increase the probability of the Winner’s Curse and the overall degree of overpayment. Key determinants include the number of unique bidders inducing auction fever, the psychological effect of anchoring through the starting price, and the tendency to ignore additional shipping costs due to mental accounting. The analysis also proves that the sniping strategy works as an effective rational defense that reduces the probability of the Winner’s Curse and the overpayment amount itself. The findings challenge the universal validity of the full rationality model even for highly homogeneous investment assets and confirm the crucial role of behavioral factors in the online auction environment.